How to add insulation & cost?

mushMarch 23, 2008

This is my house. Built in the early 30's. I don't think there is any insulation in the outside walls. When it gets really cold the walls are like ice to the touch. What would it cost to have someone blow in insulation? Is this what I should do? What are my options? How is it done? I am clueless about this, but know I need to do something. It's a small house. Two bedrooms and bath upstairs.

As others here have pointed out, look first to doing the easy things to save energy and increase comfort. That means insulating the attic and upper basement walls and sealing up all the places that air can flow into the conditioned space in your home.

You see that big melted area on your roof? The melted area means that warm air is leaking from the living space and pushing your dollars literally thru the roof. I would check the attic space to see what kind and what levels of insulation exist. Where do you live? You might need at least R38 to R49. Also based on the way the house looks it seems you might have some kneewalls in the 2nd floor. In fact the melted area looks to be the top of a kneewall. Those are the short walls that meet a sloping ceiling. Be sure that there is proper insulation behind these walls and on the floor behind it. Or if there is a crawlspace storage area it should have an air barrier and insulation along the slope. Stopping the air from leaking out the top of the house with airsealing and insulation is the cheapest and usually the first step done in correcting comfort issues. Walls generally should be done much later after everything else is done. For wall insulation whats done with cellulose is they drill 2 inch holes from the outside or inside and use a hose to blow it in. Works great but cost will depend on your area. I just finished blowing in cellulose in my home around 2000sqft and i spent 900 dollars for the cellulose and did all the work myself. A few yrs ago i had the job quoted for me around 2300.

I'll chime in, too, since I just had this done. We live in the Cleveland area and that snow in your photo looks mighty familiar!

DH and son blew cellulose into our 2000 sf attic and the total cost was about $600, after a 10% discount from Lowes. It took only about 100 bags, since some of the attic is used for storage so the insulation is only under the plywood and therefore not as thick in this area. We know it would be better insulated if we gave up the storage space, but it's nice and thick everywhere else. They also used Great Stuff foam to close up all the air penetrations into the attic, and also around the one area of the basement that is a crawl space. Blowing in the insulation took one day (a long day) and preparing the attic (moving all the stuff, taking up the plywood, etc) took another couple of days.

We then had a contractor come in and pack cellulose into the walls. He estimated about 1500 sf and it cost us $1800, including doing the walls of the stairs to the attic inside the house since it is unheated space on one side and heated on the other. This took their crew of four people one day. They drilled holes outside, but removed the siding so you can't see the holes at all. Our home is a cedar-sided single story ranch built in 1957 that had no insulation in the walls or attic.

We've already noticed a big difference, but the first gas bill will tell the real story.

Up here in Maine -- very familiar snow here, too -- the estimate for a local company to do the blown-in cellulose in my 1400sf 1922 hollow-walled bungalow was around $1600. Turns out my attic was already insulated, so I did the exterior walls myself for a total of about $600 including the rental of the machine and a handyman to help out. I had extra, so went ahead and did the interior walls also -- cellulose is a great acoustic insulator, the place feels much quieter and more solid. Not to mention immediately warmer.

I hear you on the icy walls -- the reason I began looking into this was hearing my drywall plasterer complain that his mud was taking forever to dry on all the exterior walls.

(DIY tips: don't use the Lowe's "free" machine, rent a higher-caliber one elsewhere; use a dedicated electrical circuit if possible; make sure to drill two holes for every stud bay to allow for air to escape and get the tightest packing; get a huge sponge and slide it over the end of the blower hose to eliminate blowback.)

I live in MA and had this done in our house last year. We have a 1890 farmhouse style which is about 2100 square feet. They used blown in insulation made from recycled newspaper. At the time the local gas company was underwriting a % of the cost and we were able to deduct some from our taxes as well -- I am not sure if that program is in place anymore, but it is worth checking out. Total cost was about $2300 and cost to us about $1600 (don't remember exactly).

We plan on closed cell polyurethane foam in our open walls, but you can also get a slow rising variety. This can be a DIY application. I found a youtube vid of one application, below. I also tried to embed it.

One caution about blown in insulation and stucco. Are they doing it from the inside? We did that so they wouldn't put holes in the exterior stucco of one house. They said they would "fill the holes" after adding the insulation -- only problem was they didn't fill them evenly, so we had to go around mudding and smoothing out all those annoying holes in between ALL those wall cavities. Write in the contract that it will be done evenly and to your satisfaction and don't pay the whole bill until you see it done!